What is causing brake squeal on my Zafira?

I have a 2007 Vauxhall Zafira that has very annoying squeal. It started in June 2012 and I hear it on almost every journey, intermittently. It appears to come from the driver front wheel. If I stop the car, the noise stops, and it starts at any point. I mentioned it to Vauxhall in December when it went in for a service and MoT. They said there was nothing wrong except a very small amount of rust / corrosion on the brake disc which the pad is rubbing against, but this should wear off. I just wondered if this loud squeal really could be just the pad rubbing and also why would it be intermittent?

Asked on 23 March 2013 by RS, St Albans

Answered by Honest John
Brake discs corrode continuously, especially in cold, wet and salty/wet conditions. Normally, application of the brakes means that the pads scrape off the surface corrosion on the discs, but pads now also have metallic content. So the squealing is its of metal in the pads rubbing against the brake discs. Check your mirrors carefully first and on a dry surface try some heavy braking. That might cure it. If that doesn't solve the problem, new pads might. Yet another factor is dirty caliper pins that are preventing the calipers that hold the pads from springing back completely.
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